Semax is a synthetic peptide analog of adrenocorticotropic hormone (ACTH) (4-10) that has neuroprotective, analgesic, and anxiolytic properties.1,2,3 In vivo, semax (0.3 mg/kg) reduces cortical nitric oxide (NO) production and the number of neurological disturbances, such as seizures, falling, and twisting, in a rat model of global ischemia.1 It decreases acetic acid-induced writhing and nociception in a hind paw compression test in mice when administered at doses ranging from 0.015 to 0.5 mg/kg.2 Semax also increases time spent in the open arms in the elevated plus maze, indicating anxiolytic activity, in a rat model of maternal deprivation-induced anxiety.3

References
1. Bashkatova, V.G., Koshelev, V.B., Fadyukova, O.E., et al. Novel synthetic analogue of ACTH 4-10 (Semax) but not glycine prevents the enhanced nitric oxide generation in cerebral cortex of rats with incomplete global ischemia. Brain Res. 894(1), 145-149 (2001).
2. Ivanova, D.M., Levitskaya, N.G., Andreeva, L.A., et al. Comparative study of analgesic potency of ACTH4-10 fragment and its analog semax. Bull. Exp. Biol. Med. 143(1), 5-8 (2007).
3. Volodina, M.A., Sebentsova, E.A., Glazova, N.Y., et al. Semax attenuates the influence of neonatal maternal deprivation on the behavior of adolescent white rats. Bull. Exp. Biol. Med. 152(5), 560-563 (2012).